A few days (weeks?) ago, I went to backup my Windows drive. Simple enough, right? Unless you're an idiot like me, and somehow borked something to the point that the Clonezilla storage drive you're using won't save it anymore, even thought it has plenty of free space.
Time to transfer the contents of that drive to the 2TB RAID1 array. Oh wait... never got around to fixing the server. It's still running as two gimped partitions, neither of which have enough space, though the 2TB isn't nearly full.
Time to fix that... except it contains the only "known good" copy of the data. After using "rsync" to backup to an external drive, as is my backup procedure (terrible, I know), it was time to get to work.
Except I forgot how I setup my server. I knew it wasn't pretty, but I didn't document it. I figured it was set-and-forget. How right I was. I haven't had any issues with it (thanks, Debian!), but I also forgot how to use it.
Fortunately, I'm a Debian-family Linux dude, so it didn't take me too long (with Google's help, of course) to figure out. I used "mdadm" and "lvm" on my Xen host, and did everything else (mounting and serving) from a Xen guest.
Then, I had issues transferring everything back. Several days later, all was back to normal.
I still need to back up my Windows drive.